I did a complete fluid change (oil, transmission, transfer case, front diff., rear diff., and engine coolant) at 70K and I am thinking of doing the O2 sensors since I also cleaned the throttle body and MAF and changed the plugs, coils, and fuel filter when I did the fluid change. As far as I can tell there is one in the center of each cat which is backed up by Ford Parts diagram. Has anyone changed them out and what did you replace with (motorcraft, bosch, etc.)? Any complaints on a brand?

Motorcraft part #'s 9F472 (left side cat) and 9G444 (right side cat)

 

I like the NTK's.

 

I just recently replaced all 4 O2 sensors. You're going to need the O2 wrench for it. Found one at Autozone for $18.00. Its pretty nifty. Made just for our trucks. Looks like a ratchet with a built on socket. only the socket is only about an inch deep. swivel handle is very nice and gets into the tight spots perfectly. I used the Bosh sensors. If you buy them in a local parts store, its going to set you back about 79.00/ea. I bought my (not a plug) at RockAuto Auto Parts at 40.00/ea. NOTE that upper O2 sensor on the left side (passenger) is very hard to get to. unplugging it and pulling it out is simple. Re-installing it, very different story. make sure you thread in the sensors PRIOR to connecting them, otherwise you'll twist the wires all up causing a short. Now that left upper sensor is going to give you trouble when you go to connect it back in. I had to lay under the truck with a flashlight, reaching an arm in through the fender well over the exhaust and behind the block to reach the connector. Make sure your engine is DEAD COLD!!! or you're going to burn the ever loving out of your arm. its a tight fit, someone else may have a better way, but I had cuts on the back of my hand and arm from this for a week. the other three, less than 15 min total time to change. Hope that helps.

Rob

 

Looking to change my sets today the passenger side front looks the be hell to get the connecter off any one know the easy